Conversion of biomass to adsorbent: a review

Tons of biomass are produced every year including organic agricultural and forestry by-products but they are of limited value. Mostly, in the developing countries, the biomasses are considered as waste and are being burnt or thrown to liter the environment as part of teaming solid waste. Presently, there are no sustainable long-term management strategies to use biomass. The utilization of biomass to produce activated carbon is a good approach that is industrially useful and environmentally benign materials. The adsorption technique is using adsorbents in the removal of heavy metals from water therefore, biomass can be converted to the adsorbent and utilized as a waste-to-wealth commodity in water purification. In this review, the suitable process for conversion of biomass to cheap and simple means of obtaining activation carbon as adsorbent is presented. The potential uses of biomass and the conversion stages including carbonization, pyrolysis, gasification, and activation were discussed. This work depicts that the issue of solid waste utilization to solve existing issues with locally available and cheap materials is beneficial to man and the environment

Enhancing Oil Recovery through Waterflooding

Waterflooding is a simple and cheaper means of improving oil recovery from a reservoir by injecting water into the reservoir. Economic considerations suggest injection and production wells must be optimally placed considering reservoir geology, fluid properties, and well orientation. This study focuses on the effects of well placement and orientation on the performance of waterflooding process. The reservoir has a dimension of 2500 ft by 2500 ft by 150 ft. It is homogenous in porosity and heterogeneous in permeability. The performances of three cases considered in the study were evaluated and compared. Water production rates, bottom hole pressure limits for producer wells, well water cut and net present value (NPV) over the entire production period were considered in evaluating their performances. Reservoir modeling and simulation were carried out using MATLAB Reservoir Simulation Toolbox (MRST). It was verified from the investigation that Case III has a maximal production rate of 1,110,188.6 stb/day (stock tank barrel per day), decreasing to 11,005 stb/day after a span of 1400 days with a pressure decrease. Consequently, it was considered a better choice in terms of well placement. It was also estimated to have a maximal Net Present Value of 19.8 billion dollars, which makes it economically viable

Conversion of Biomass to Adsorbent: A Review

Tons of biomass are produced every year including organic agricultural and forestry by-products but they are of limited value. Mostly, in the developing countries, the biomasses are considered as waste and are being burnt or thrown to liter the environment as part of teaming solid waste. Presently, there are no sustainable long-term management strategies to use biomass. The utilization of biomass to produce activated carbon is a good approach that is industrially useful and environmentally benign materials. The adsorption technique is using adsorbents in the removal of heavy metals from water therefore, biomass can be converted to the adsorbent and utilized as a waste-to-wealth commodity in water purification. In this review, the suitable process for conversion of biomass to cheap and simple means of obtaining activation carbon as adsorbent is presented. The potential uses of biomass and the conversion stages including carbonization, pyrolysis, gasification, and activation were discussed. This work depicts that the issue of solid waste utilization to solve existing issues with locally available and cheap materials is beneficial to man and the environment

Optimization and Non-Linear Identification of Reservoir Water Flooding Process

In this study, dynamic optimization and identification of petroleum reservoir waterflooding using receding horizon (RH) principles was examined. Two forms of the strategy were compared on a realistic reservoir model. Sequential quadratic programming (SQP) was applied to optimize net present value (NPV) using water injection rates as the variables. MRST from SINTEF was used for the reservoir modeling. The identification of the reservoir was performed using nonlinear autoregressive with exogenous input (NARX) neural network from MATLAB. Data for the network training and validation was obtained by carrying out a numerical experiment on a high fidelity model of the reservoir. This model was developed with Eclipse Reservoir Simulator from Schlumberger. From the results obtained, moving-end RH gave a higher NPV than fixed-end RH with a margin of $0.5 billion. The identification algorithm was very much effective and near perfect for the studied reservoir

DnaK Chaperone-Mediated Control of Activity of a ς(32) Homolog (RpoH) Plays a Major Role in the Heat Shock Response of Agrobacterium tumefaciens

RpoH (Escherichia coli ς(32) and its homologs) is the central regulator of the heat shock response in gram-negative proteobacteria. Here we studied salient regulatory features of RpoH in Agrobacterium tumefaciens by examining its synthesis, stability, and activity while increasing the temperature from 25 to 37°C. Heat induction of RpoH synthesis occurred at the level of transcription from an RpoH-dependent promoter, coordinately with that of DnaK, and followed by an increase in the RpoH level. Essentially normal induction of heat shock proteins was observed even with a strain that was unable to increase the RpoH level upon heat shock. Moreover, heat-induced accumulation of dnaK mRNA occurred without protein synthesis, showing that preexisting RpoH was sufficient for induction of the heat shock response. These results suggested that controlling the activity, rather than the amount, of RpoH plays a major role in regulation of the heat shock response. In addition, increasing or decreasing the DnaK-DnaJ chaperones specifically reduced or enhanced the RpoH activity, respectively. On the other hand, the RpoH protein was normally stable and remained stable during the induction phase but was destabilized transiently during the adaptation phase. We propose that the DnaK-mediated control of RpoH activity plays a primary role in the induction of heat shock response in A. tumefaciens, in contrast to what has been found in E. coli