Biomass pyrolysis is a promising renewable sustainable source of fuels and petrochemical substitutes. It may help in compensating the progressive consumption of fossil-fuel reserves. The present article outlines biomass pyrolysis. Various types of biomass used for pyrolysis are encompassed, e.g., wood, agricultural residues, sewage. Categories of pyrolysis are outlined, e.g., flash, fast, and slow. Emphasis is laid on current and future trends in biomass pyrolysis, e.g., microwave pyrolysis, solar pyrolysis, plasma pyrolysis, hydrogen production via biomass pyrolysis, co-pyrolysis of biomass with synthetic polymers and sewage, selective preparation of high-valued chemicals, pyrolysis of exotic biomass (coffee grounds and cotton shells), comparison between algal and terrestrial biomass pyrolysis. Specific future prospects are investigated, e.g., preparation of supercapacitor biochar materials by one-pot one-step pyrolysis of biomass with other ingredients, and fabricating metallic catalysts embedded on biochar for removal of environmental contaminants. The authors predict that combining solar pyrolysis with hydrogen production would be the ecofriendliest and most energetically feasible process in the future. Since hydrogen is an ideal clean fuel, this process may share in limiting climate changes due to CO 2 emissions.

Self-bonding of air dry undebarked cotton stalks during hot pressing in a closely fitting mold was studied. Advanced board like green nanocomposites from ground undebarked cotton stalks were introduced, for the first time, in the present work. The dry forming process was adopted. Moderate molding pressure and temperature were selected and applied in a tight die. Thus saving water, energy, and avoiding the use of any binders; to achieve an environment friendly green product. Green Nanocomposites having densities in the range 1.27-1.29g/c.c. as well as 1.03-1.06 g/c.c. were prepared. It was found that particle size, and cell wall morphological structure play a great role in se1f bonding.Properties of composites prepared from the fine fraction of cotton stalks were superior to those prepared from cotton stalks coarse fraction at same conditions. This is attributedamong other things -to the dominance of pith (parenchyma cells) in the fine fraction. Such cells possess a high lumen to cell wall ratio, which renders them more deformable under pressure leading to more intercellular or interparticle bonding. Advanced Binderless Green Nanocomposites having bending strength as high as 637 Kg/cm 2 and water absorption as low as 12.1% were obtained from the ground undebarked cotton stalks. The results show clearly that the advanced green nanocomposite obtained by dry forming process, without addition of any binders, is superior to hardboard obtained from cotton stalks by the conventional wet web formation process. The mechanism of self-bonding was discussed.

This work introduces, for the first time worldwide, an advanced nanocomposite involving two additives-a nanoadditive and a conventional additive-within a matrix of natural cellulose fibers. The first additive (the nanoadditive) is sucrose, which incorporates the nanoporous structure of the cell walls of cellulose fibers. The second additive (the conventional additive) is kaolin, the famous paper filler. Kaolin is enmeshed between the adjacent cellulose fibers. This advanced paper nanocomposite was prepared by simple techniques. The present work shows, for the first time, that sucrose can overcome the ultimate fate of deterioration in strength of paper, due to addition of inorganic fillers such as kaolin. This deterioration was counteracted by incorporating cellulose fibers with sucrose, which leads to incorporation beating of the fibers, and thus increases the strength of the produced paper nanocomposites. In addition, sucrose was proven-for the first timeto act as retention aid for inorganic fillers such as kaolin. We called this phenomenon incorporation retention to differentiate it from the conventional types of retention of inorganic fillers. Recent studies, by the authors and others, have shown that incorporating cellulose fibers, with sucrose, leads to paper nanocomposites of enhanced strength (breaking length). Also, sucrose is privileged by its small size (0.8nm), substantial hydrogen bonding capacity, low cost, and p 3 of 21 tp abundance. Therefore, sucrose was chosen as a nanoadditive in this work. The present study shows that the nanoadditive sucrose may find its use as a new retention aid and strength promoter in papermaking. p 4 of 21 tp

It is shown for the first time world wide, in the present work, that sucrose can be easily placed by simple techniques within the micropores or nanostructure of the mercerized non-dried cotton linters fibers to create a low cost cellulose substitute. Such sucrose-containing nanocomposites find their suitable uses as specialty absorbent paper. Relative to the sucrose-free paper, the sucrose-containing counterparts exhibit greater breaking length and remarkably high water uptake (W.R.V.) up to sucrose-content 8-15 % w/w. Mercerization of cotton linters, before incorporating them with sucrose, greatly enhanced the retention of sucrose in the prepared paper nanocomposites as compared to the case of unmercerized cotton linters. We assume that regions of the cell wall lamellae, on both sides of the sucrose spacers, are stressed during drying because the sucrose spacers hinder them to relax. This leads to a strain, which makes some microfibrils be partially released and protrude out of the fiber. Thus a sort of fiber beating takes place. We called this phenomenon Incorporation-Beating or Encapsulation-Beating to differentiate it from chemical and mechanical beating; and it explains the great increase in breaking length of the paper nanocomposites prepared from the mercerized non-dried sucrose-loaded linters.

This work introduces, for the first time worldwide, the means to preserve and protect the natural nanoporous structure of the never-dried plant cell wall, against the irreversible collapse, which occurs due to drying. Simultaneously, these means, used for the above-mentioned aim, provide a gateway to novel nanocomposite materials, which retain the super reactive and super absorbent properties of the never-dried biological cellulose fibers. The present work showed, for the first time worldwide, that glucose can be vaccinated into the cell wall micropores or nanostructure of the never-dried biological cellulose fibers, by simple new techniques, to create a reactive novel nanocomposite material possessing surprising super absorbent properties. Inoculation of the never dried biological cellulose fibers, with glucose, prevented the collapse of the cell wall nanostructure, which normally occurs due to drying. The nanocomposite, produced after drying of the glucose inoculated biological cellulose, retained the super absorbent properties of the never dried biological cellulose fibers. It was found that glucose under certain circumstances grafts to the never dried biological cellulose fibers to form a novel natural nanocomposite material. About 3-8% (w/w) glucose remained grafted in the novel nanocomposite.