Differential Catalysis of Depolymerisation and Dehydration Reactions: Producing Furfural from Plant Biomass

The main principles of the technological realisation of the furfural obtaining process have been formulated by Ricard[1].Based on his recommendations,all investigators proceeded from the assumption that the depolymerisation of pentosans and the dehydration of pentoses in the one-step production of furfural from raw plant material must be accelerated with diluted catalyst solutions.According to this theory,uniform impregnation of the raw material with a catalyst solution is considered necessary.The reduction in the amount of the catalyst solution down to 30–40%of the mass of the dry raw material,suggested by Miner et al.[2],made the process of furfural production profitable and it prompted industrial production.Their technology is being successfully using also now at more than 140 furfural plants in China,where the furfural yield is only 45%of the theoretical yield and 50%of the cellulose in the lignocellulosic residue is destroyed during the process of obtaining furfural.Therefore,the residue of the raw material after furfural production may only be used as fuel or fertiliser.A simultaneous solution to these two problems has not been possible without changing the chemical mechanism of the depolymerisation and dehydration reactions during the furfural formation process.Using birch wood as a raw material,we simultaneously addressed these two problems using the following two catalysts:acetic acid for the depolymerisation of pentosans and concentrated sulfuric acid for the dehydration of pentoses,producing furfural.As a result,the furfural yield increased and the new furfural production technologies from hardwood and other raw plant materials were realised at 10 plants in 3 countries.A licence was sold,and contracts with companies in Slovenia,Hungary and Russia were successfully performed.

Overexpression of the recombinant xyloglucanase <i>sp-Xeg</i>from <i>Penicillium canescens</i>accelerates growth and rooting of transgenic aspen plants

Analysis of the properties of transgenic aspen clones with recombinant gene xyloglucanase sp-Xeg from fungi Penicillium canescens showed the presence of complex modifications both in the wood and the phenotype of plants. Biometric analysis revealed an increase in the height of transgenic plants as compared to control plants. Increasing in the height of the shoot of 24.8%, 25% and 26% was observed for lines PtXIVXeg1a, PtXVXeg1a, PtXVXeg1b, respectively. Also there was an increase in the number of internodes in some transgenic clones. For the first time we showed the change in plants rhizogenesis with the recombinant gene xyloglucanase. In 10 of the 25 lines the rooting efficiency in vitro exceeded the control value. The maximum value of the rhizogenesis was fixed for line PtXVXeg1a (2.5 times higher than the control value). The mass of the root system for 6 of the 25 clones in the greenhouse was higher by 20% than the control value. The pentosan content decrease was also detected in all wood samples of transgenic plants. The obtained data of xyloglucanase activity and pentosan content generally correlated with phenotypic modifications.

Relationships between high-molecular-weight glutenin subunit （HMW-GS）, pentosan and various component contents in different wheat varieties

The composition of HMW-GS and pentosan and its various component contents in different wheat varieties were analyzed. According to scores of these subunits in several wheat varieties, the correlation relationship between the composition of HMW-GS, subunit combination types and pentosan, various components and component ratio were ascertained. The results showed that HMW-GSs were very diverse which had 11 types. In different varieties, the variation of Ara was obvious while Xyl was not; pentosan and its various component contents were very different, and their coefficient of variability was quite high. The majority of parameters had a significant negative correlation with Glu-1 where Glu-D1 was stronger than other two loci. N, 7, 17＋18 and 2＋12 subunits had influence on pentosan and its various component contents. But some subunits such as 1 and 5＋ 10 which are good for baking quality had little contribution to pentosan and various component contents. The pentosan and various component contents were higher in the varieties which had （N, 7, 2＋12） subunit combinations. Additionally, the 21 varieties were classified into 4 categories according to HMW-GS scores and pentosan content.

Variation of chemical characteristics and pulpability of dhaincha(Sesbania bispinosa)on location

Dhaincha(Sesbania bispinosa(Jacq.)Wight)is a crop generally cultivated for improving soil quality.Due to the lack of forest worldwide,alternative source of raw materials for cellulose industries is the main concern today.In this investigation,dhaincha samples of 21 accessions were collected from different districts of Bangladesh in order to study the variation of chemical characteristics and its pulpability.The lignin,pentosan andα-cellulose content were varied from 21 to 23%,16 to 18%and 38 to 43%,respectively.The highest and lowestα-cellulose contents were found in two location of Mymensingh district.There was no correlation was found among the districts.Therefore,pulping of dhaincha from selected seven districts was carried out in kraft process at the conditions of 18%active alkali at 170℃ for 2 h.But the pulping properties did not show any mentionable distinction for place variation.Average pulp yield is 42.9%with kappa number 11.The highest brightness 85%was reached with D_(0)E_(p)D_(1)bleaching.The papermaking properties were very close to the conventional raw materials used in Bangladesh.Therefore,dhaincha can be used as a raw material for pulp production in Bangladesh.