Current Developments in Thermochemical Conversion of Biomass to Fuels and Chemicals

Biomass is one of the largest concentrated carbon source available for producing renewable energy. Thermochemical conversion of biomass has been used for centuries in various settings. Biomass typically has a higher oxygen and volatile matter content than other solid carbon feedstocks, resulting in increased reactivity during conversion by thermochemical pathways. Moisture content of the biomass feedstock exerts significant influence on the conversion process and is an important criteria used to classify various thermochemical conversion technologies. This chapter discusses the current status and future outlook of thermochemical biomass conversion processes

Potential effect of age of BCG vaccination on global paediatric tuberculosis mortality: a modelling study.

BACKGROUND: BCG has been recommended at birth in countries with a high tuberculosis burden for decades, yet delayed vaccination is widespread. To support a WHO guidance review, we estimated the potential global tuberculosis mortality benefit of administering BCG on time and consequences of later administration. METHODS: We estimated age-specific BCG coverage in 152 high-burden countries using data from large, nationally representative household surveys, to parameterise a static mathematical model, calibrated to global childhood tuberculosis deaths in 2016. 12 hypothetical scenarios explored the effect of BCG delivery at birth, 6 weeks, 6 months, or 9-12 months, on tuberculosis deaths per global birth cohort by age 15 years, including delivery at the time of the first diphtheria-tetanus-pertussis vaccine (DTP1) or the first measles-containing vaccine (MCV1). We assumed constant vaccine efficacy by age, but varied coverage and degree of vaccination delay, including no delay. FINDINGS: In 152 high-burden countries, we estimated that BCG coverage in 2016 was 37% at 1 week of age, 67% at 6 weeks, and 92% at 3 years. Modelled scenarios in which 92% BCG coverage was achieved at birth reduced tuberculosis deaths in the global birth cohort by 5449 (95% uncertainty range 218-15 071) or 2·8% (0·1-7·0) by age 15 years. 100% coverage at birth reduced tuberculosis deaths by 16·5% (0·7-41·9). Later administration increased tuberculosis deaths-eg, BCG vaccination at 6 weeks, the recommended age of DTP1, increased tuberculosis deaths by 0·2% (0-0·4), even if BCG reached DTP1 coverage levels (94% at 3 years). INTERPRETATION: Reducing delays and increasing coverage at birth would substantially reduce global paediatric tuberculosis mortality. Modelled scenarios whereby BCG was administered later in the infant schedule were all estimated to increase tuberculosis deaths, even with increased coverage. The WHO recommendation for BCG at birth should be maintained and emphasised. FUNDING: WHO

Impact of COVID-19 Disruptions on Global BCG Coverage and Paediatric TB Mortality: A Modelling Study.

The impact of COVID-19 disruptions on global Bacillus Calmette-Guérin (BCG) coverage and paediatric tuberculosis (TB) mortality is still unknown. To fill this evidence-gap and guide mitigation measures, we estimated the impact of COVID-19 disruptions on global BCG coverage and paediatric TB mortality. First, we used data from multiple sources to estimate COVID-19-disrupted BCG vaccination coverage. Second, using a static mathematical model, we estimated the number of additional paediatric TB deaths in the first 15 years of life due to delayed/missed vaccinations in 14 scenarios-varying in duration of disruption, and magnitude and timing of catch-up. We estimated a 25% reduction in global BCG coverage within the disruption period. The best-case scenario (3-month disruption, 100% catch-up within 3 months) resulted in an additional 886 (0.5%) paediatric TB deaths, and the worst-case scenario (6-month disruption with no catch-up) resulted in an additional 33,074 (17%) deaths. The magnitude of catch-up was found to be the most influential variable in minimising excess paediatric TB mortality. Our results show that ensuring catch-up vaccination of missed children is a critical priority, and delivery of BCG alongside other routine vaccines may be a feasible way to achieve catch-up. Urgent action is required to support countries with recovering vaccination coverages to minimise paediatric deaths

Disregarding the restrictive vial-opening policy for BCG vaccine in Guinea-Bissau: impact and cost-effectiveness for tuberculosis mortality and all-cause mortality in children aged 0-4 years.

OBJECTIVE: BCG vaccination is frequently delayed in low-income countries. Restrictive vial-opening policies, where a vial of BCG vaccine is not opened for few children, are a major reason for delay. During delays, children are unprotected against tuberculosis (TB) and deprived of non-specific effects of BCG. We assessed the potential effect and cost-effectiveness of disregarding the restrictive vial-opening policy, on TB and all-cause mortality, in children aged 0-4 years in Guinea-Bissau. METHODS: Using static mathematical models, we estimated the absolute and percentage change in TB and all-cause deaths, in children aged 0-4 years, between the current BCG vaccine restrictive-opening policy scenario, and a non-restrictive policy scenario where all children were vaccinated in the first health-facility contact. Incremental cost-effectiveness was estimated by integration of vaccine and treatment costs. FINDINGS: Disregarding the restrictive BCG vial-opening policy was estimated to reduce TB deaths by 11.0% (95% uncertainty range (UR):0.5%-28.8%), corresponding to 4 (UR:0-15) TB deaths averted per birth cohort in Guinea-Bissau, resulting in incremental cost-effectiveness of US$911 per discounted life-year gained (LYG) (UR:145-9142). For all-cause deaths, the estimated reduction was 8.1$ 9 (UR:5-23) per discounted LYG. CONCLUSIONS: Disregarding the restrictive BCG vial-opening policy was associated with reductions in TB deaths and all-cause deaths and low cost-effectiveness ratios. Our results suggest that it would be cost-effective to disregard the restrictive vial-opening policy. Other settings with similar practice are also likely to gain from disregarding this policy

Uptake of infant and preschool immunisations in Scotland and England during the COVID-19 pandemic: An observational study of routinely collected data

Funding: This analysis was part of the EAVE II project. EAVE II is funded by the Medical Research Council (MC_PC_19075), https://mrc.ukri.org/, with the support of BREATHE: the Health Data Research Hub for Respiratory Health (MC_PC_19004), https://www.hdruk.ac.uk/helping-with-health-data/health-data-research-hubs/breathe, which is funded through the UK Research and Innovation Industrial Strategy Challenge Fund and delivered through Health Data Research UK.Background In 2020, the SARS-CoV-2 (COVID-19) pandemic and lockdown control measures threatened to disrupt routine childhood immunisation programmes with early reports suggesting uptake would fall. In response, public health bodies in Scotland and England collected national data for childhood immunisations on a weekly or monthly basis to allow for rapid analysis of trends. The aim of this study was to use these data to assess the impact of different phases of the pandemic on infant and preschool immunisation uptake rates. Methods and findings We conducted an observational study using routinely collected data for the year prior to the pandemic (2019) and immediately before (22 January to March 2020), during (23 March to 26 July), and after (27 July to 4 October) the first UK “lockdown”. Data were obtained for Scotland from the Public Health Scotland “COVID19 wider impacts on the health care system” dashboard and for England from ImmForm. Five vaccinations delivered at different ages were evaluated; 3 doses of “6-in-1” diphtheria, tetanus, pertussis, polio, Haemophilus influenzae type b, and hepatitis B vaccine (DTaP/IPV/Hib/HepB) and 2 doses of measles, mumps, and rubella (MMR) vaccine. This represented 439,754 invitations to be vaccinated in Scotland and 4.1 million for England. Uptake during the 2020 periods was compared to the previous year (2019) using binary logistic regression analysis. For Scotland, uptake within 4 weeks of a child becoming eligible by age was analysed along with geographical region and indices of deprivation. For Scotland and England, we assessed whether immunisations were up-to-date at approximately 6 months (all doses 6-in-1) and 16 to 18 months (first MMR) of age. We found that uptake within 4 weeks of eligibility in Scotland for all the 5 vaccines was higher during lockdown than in 2019. Differences ranged from 1.3% for first dose 6-in-1 vaccine (95.3 versus 94%, odds ratio [OR] compared to 2019 1.28, 95% confidence intervals [CIs] 1.18 to 1.39) to 14.3% for second MMR dose (66.1 versus 51.8%, OR compared to 2019 1.8, 95% CI 1.74 to 1.87). Significant increases in uptake were seen across all deprivation levels. In England, fewer children due to receive their immunisations during the lockdown period were up to date at 6 months (6-in-1) or 18 months (first dose MMR). The fall in percentage uptake ranged from 0.5% for first 6-in-1 (95.8 versus 96.3%, OR compared to 2019 0.89, 95% CI 0.86– to 0.91) to 2.1% for third 6-in-1 (86.6 versus 88.7%, OR compared to 2019 0.82, 95% CI 0.81 to 0.83). The use of routinely collected data used in this study was a limiting factor as detailed information on potential confounding factors were not available and we were unable to eliminate the possibility of seasonal trends in immunisation uptake. Conclusions In this study, we observed that the national lockdown in Scotland was associated with an increase in timely childhood immunisation uptake; however, in England, uptake fell slightly. Reasons for the improved uptake in Scotland may include active measures taken to promote immunisation at local and national levels during this period and should be explored further. Promoting immunisation uptake and addressing potential vaccine hesitancy is particularly important given the ongoing pandemic and COVID-19 vaccination campaigns.Publisher PDFPeer reviewe

Development of Technologies for RNG Utilization

Renewable energy production processes have achieved significant technological and commercial maturity over the past two decades. Most carbon based renewable fuel gases contain significant quantities of CO2. Converting the CO2 along with methane into syngas is an attractive option since it can potentially increase utilization of distributed renewable carbon resources while creating additional revenue streams.An integrated renewable power generation system where the SBR process was coupled with a Solid Oxide Fuel Cell (SOFC) was studied using the Aspen Plus model. The steam-biogas reforming (SBR) process performed over a Pd-Rh catalyst was compared with equilibrium values predicted by Aspen Plus. At steam to carbon ratio of 1.50 and temperature of 1073 K or above, positive CO2 conversion was obtained. Coke formation was significantly reduced during reforming reaction performed experimentally over the Pd-Rh compared to literature data. SBR integrated with combustion process works with an efficiency of 40% or higher. The variation of the catalytic support material composition helps to adjust H2/CO ratio and H2/CH4 yield. CeZrO2 addition suppressed coke formation, for improved oxygen storage and oxide reducibility. Pd-Rh catalysts exhibit stable performance for 200 h, although sintering occurred regardless the catalyst composition used.A life cycle assessment was performed for methanol production pathway using syngas produced via bi-reforming pathway from CO2, H2O reforming with methane. GHG emission is about 203 kilograms of CO2e per metric tonne of methanol produced using the proposed bi-reforming pathway. GHG emission reduction is 0.29 kg/ CO2e/kg of CH3OH compared to the commercial scale production. With NG price $3.50/GJ and methanol price$400/tonne IRR is 57% with 5 years payback period.A database for Wobbe Index, Methane Number, thermal conductivity, sound velocity of biogas, anaerobic digester gas and natural gas mixture was built. A prediction model for WI and MN of a gaseous fuel mixture was developed that uses thermal conductivity and sonic velocity. The model can predict the Wobbe Index with an average error of ±2.76% and Methane Number with an average error of ±1.65%. The prediction model coupled with a thermal conductivity sensor and sonic velocity measurement sensor enables the combustion of gas efficiently

Development of Key-Enabling Technologies for a Variable-blend Natural Gas Vehicle

A portable, economic and reliable sensor for the Natural Gas (NG) fuel quality has been developed. Both Wobbe Index (WI) and Methane Indexes (MI) as well as inert gas content (inert%) of the NG fuel can be measured in real time within 5% accuracy. This sensor is targeting to be used in any equipment that involves NG combustion including NG vehicle, boiler, building HVAC, various consumer level gas appliance and Variable Natural Gas Vehicle (VNGV). The VNGV is an NG vehicle that can operate on any arbitrary mixture of CH4 and CO2, thus allowing the use of Renewable Natural Gas (RNG) including biogas for transportation without comprehensive gas cleanup/upgrading. The technology behind is to predict the “Value of Interests” (WI, MI and inert%) by the signals from easily “Measurable Physical Properties” (such as thermal conductivity, temperature, etc..), as shown in the figure. Prediction of “Value of Interest” by data mining (esp. Multivariate Analysis and/or Artificial Neural Network) is the key idea of the concept. This technology is non-invasive, rugged, and small in size promising to overcome limitations and shortcomings such as bulky size and intrusive nature of conventional measurement technology. VNGV technology will enable widespread use of RNG as a transportation fuel, resulting in significant reductions in GHG emissions in the transportation sector.View the NCST Project Webpag