Steam reforming of phenol as biomass tar model compound over Ni/Al₂O₃ catalyst

Catalytic steam reforming of phenol over Ni/Al₂O₃ catalyst with 10 wt% of Ni loading was carried out in a fixed bed reactor. The effect of temperature (650–800 °C), reaction time (20–80 min) and catalyst amount (0–2 g corresponding to 0–4.5 gcat h gphenol−1) on carbon conversion, H2 potential and catalyst deactivation was studied. High efficiency of Ni/Al₂O₃ catalyst in steam reforming of phenol is observed at 750 °C for a reaction time of 60 min when 1.5 g of catalyst (3.4 gcat h gphenol−1) is used, with carbon conversion and H2 potential being 81 and 59%, respectively. An increase in temperature enhances phenol reforming reaction as well as coke gasification, minimizing its deposition over the catalyst. However, at high temperatures (800 °C) an increase in Ni crystal size is observed indicating catalyst irreversible deactivation by sintering. As catalyst time on stream is increased the coke amount deposited over the catalyst increases, but no differences in Ni crystal size are observed. An increase in catalyst amount from 0 to 1.5 g increases H2 potential, but no further improvement is observed above 1.5 g. It is not observed significant catalyst deactivation by coke deposition, with the coke amount deposited over the catalyst being lower than 5% in all the runs

Problemet bakom den svaga responsen av K2-regelverket : utifrån ett organisationsteoretiskt perspektiv

This study intends to explain the problem with the implementation of new Swedish accounting rules called K2. The rules are simplifications of the general accounting rules and the purpose is to make it easier for small companies to account. Despite this, few small companies have adopted the rules. This study seeks to explain the weak response to the K2-rules using institutional theory. The research objects of this study are Burger King, McDonald’s and two audits and accountants. The data is collected through telephone interviews and interviews where we visited the respondents. The interviews were semi-structured and the questions were designed so that the respondents were able to speak free. The collected data were related to the institutional theory to seek dependent variables who can explain the weak response of K2. The conclusion is that small companies are dependent of auditors and accountants when it comes to accounting. They lack knowledge about accounting, instead they purchase the service externally. The audits and accountants are in turn affected by the public opinion of K2 and they have trouble to depart from previous learning from the educational system. The explanation to the weak response of K2 is that small companies are dependent of audits and accountants who have a negative attitude towards K2 because of its illegitimacy

Pyrolysis-catalytic steam reforming of agricultural biomass wastes and biomass components for production of hydrogen/syngas

The pyrolysis-catalytic steam reforming of six agricultural biomass waste samples as well as the three main components of biomass was investigated in a two stage fixed bed reactor. Pyrolysis of the biomass took place in the first stage followed by catalytic steam reforming of the evolved pyrolysis gases in the second stage catalytic reactor. The waste biomass samples were, rice husk, coconut shell, sugarcane bagasse, palm kernel shell, cotton stalk and wheat straw and the biomass components were, cellulose, hemicellulose (xylan) and lignin. The catalyst used for steam reforming was a 10 wt.% nickel-based alumina catalyst (NiAl2O3). In addition, the thermal decomposition characteristics of the biomass wastes and biomass components were also determined using thermogravimetric analysis (TGA). The TGA results showed distinct peaks for the individual biomass components, which were also evident in the biomass waste samples reflecting the existence of the main biomass components in the biomass wastes. The results for the two-stage pyrolysis-catalytic steam reforming showed that introduction of steam and catalyst into the pyrolysis-catalytic steam reforming process significantly increased gas yield and syngas production notably hydrogen. For instance, hydrogen composition increased from 6.62 to 25.35 mmol g-1 by introducing steam and catalyst into the pyrolysis-catalytic steam reforming of palm kernel shell. Lignin produced the most hydrogen compared to cellulose and hemicellulose at 25.25 mmol g-1. The highest residual char production was observed with lignin which produced about 45 wt.% char, more than twice that of cellulose and hemicellulose