https://faculty.washington.edu/renatab/courses/PSE490/downloads/pretreatment.pdf

Features of promising technologies for pretreatment of lignocellulosic biomass.

Biofuels produced from various lignocellulosic materials, such as wood, agricultural, or forest residues, have the potential to be a valuable substitute for, or complement to, gasoline. Many physicochemical structural and compositional factors hinder the hydrolysis of cellulose present in biomass to sugars and other organic compounds that can later be converted to fuels. The goal of pretreatment is to make the cellulose accessible to hydrolysis for conversion to fuels. Various pretreatment techniques change the physical and chemical structure of the lignocellulosic biomass and improve hydrolysis rates. During the past few years a large number of pretreatment methods have been developed, including alkali treatment, ammonia explosion, and others. Many methods have been shown to result in high sugar yields, above 90% of the theoretical yield for lignocellulosic biomasses such as woods, grasses, corn, and so on. In this review, we discuss the various pretreatment process methods and the recent literature that...

http://ucce.ucdavis.edu/files/datastore/234-1388.pdf

Methods for Pretreatment of Lignocellulosic Biomass for Efficient Hydrolysis and Biofuel Production

Industrial applications of microbial lipases

Trends in bioconversion of lignocellulose: Biofuels, platform chemicals & biorefinery concept

Cellulases and related enzymes in biotechnology

The paper manufacturing process has several stages - Raw material preparation and handling, Pulp manufacturing, Pulp Washing and Screening, Chemical recovery, Bleaching, Stock Preparation, and Papermaking. Paper production is basically a two-step process in which a fibrous raw material is first converted into pulp, and then the pulp is converted into paper. The harvested wood is first processed so that the fibers are separated from the unusable fraction of the wood, the lignin. Pulp making can be done mechanically or chemically. The pulp is then bleached and further processed, depending on the type and grade of paper that is to be produced. In the paper factory, the pulp is dried and pressed to produce paper sheets. Post-use, an increasing fraction of paper and paper products is recycled. Nonrecycled paper is either landfilled or incinerated.

Brief Description of the Pulp and Paper Making Process

Biobleaching of kraft pulp

Organochlorines have been a matter of concern in the pulp and paper industry for the last two decades. These compounds are produced mainly by the reactions between residual lignin present in wood fibres and the chlorine used for bleaching. Some of the organochlorine compounds are found to be toxic, mutagenic, persistent, bioaccumulating and cause harm in biological systems.

Reduction of organochlorine compounds in bleach plant effluents

A total of 8 yeast and microbial cultures have been grown in the extract derived from the tubers of Jerusalem artichoke (Helianthus tuberosus) and screened according to the following optimization criteria: rates and yields of ethanol production, rates and yields of biomass production, and % of original sugars utilized during fermentation. Batch growth kinetic parameters were also determined for the cultures studied.

Optimization studies for the bioconversion of Jerusalem artichoke tubers to ethanol and microbial biomass

Publisher Summary This chapter reviews current wastewater management strategies for pulp and paper mill effluents that fall into three categories: pre-bleaching technologies, bleaching technologies, and post bleaching technologies. A balanced use of all the strategies is required. Treatment before disposal of bleach effluents cannot be eliminated and it will continue to play an important role in complying with the standards prescribed. Among biological treatment technologies available, fungal treatment technology appears to have an edge over the other treatment technologies. To make the fungal treatment method economically feasible, there is a need to reduce the requirement of cosubstrate or to identify a cheaper cosubstrate. A quantitative study of extracellular enzymes is also required in order to gain insight into the possible enzymatic mechanism involved in the degradation of lignin-derived compounds present in the effluents. Use of white-rot fungi can serve as a prelude to bacterial treatment and enhance bacterial removal of organic chlorine and degrade the relatively higher-molecular-weight chlorolignins.

Pratima Bajpai

Papers

Brief Description of the Pulp and Paper Making Process

Biobleaching of kraft pulp

Reduction of organochlorine compounds in bleach plant effluents

Optimization studies for the bioconversion of Jerusalem artichoke tubers to ethanol and microbial biomass

Microbial degradation of pollutants in pulp mill effluents