Adrianna Kirkman
Faculty Emeritus
Grants
There have been many changes in the past decades in natural resources higher education. The rate of change has arguably accelerated, included the terminology and outlook with regard to natural resources amongst many demographic groups that have interest in these fields of education. Arguably, 20-30 years ago a greater share of the terms used across demographic groups, such as ?forestry? and ?wood products? and ?conservation? and ?outdoor recreation?, meant the same thing (or similarly) to them all. Today the differences in understanding between the generations is greater and may have substantial effects on how higher education is viewed and valued, and what higher education offerings are most relevant, or perceived to be. Universities must be aware of and responsive to these changes in terms of recruiting, retention, preparation for work and further study, satisfaction with academic and related programming, resource allocation and strategic planning. In this study we will use survey instruments and focus groups to assess the attitudes of the public in North Carolina in regard to these kinds of features of the academy with regard to natural resources.
Simulation of a Process for Producing Ethanol It is proposed to develop process models to simulate various scenarios for producing ethanol. 1. Optimize energy balance for selected hardwood pretreatment options using process simulation software 2. Develop improved understanding of the differences between softwood and hardwood enzymatic hydrolysis, and point to new directions to more efficiently hydrolyze softwood fibers with enzymes 3. Develop economic and capital cost estimates of selected hardwood processing options
Define the next generation mill process that integrates black liquor gasification along with the Research Triangle Institute (RTI) gas cleanup technology and mini-sulfide sulfite AQ (MSS-AQ) pulping. This proposal combines three technically demonstrated technologies into an integrated process with significant energy and capital savings for the paper industry. This will include identification of the process changes necessary to generate the MSS-AQ pulping liquors using black liquor gasification, identification of pulping process conditions and the resulting product qualities, the potential benefits and a preliminary process design. In this phase of the project the proposed target will be a linerboard mill, although this technology has potential for both unbleached and bleached mills. .
NCSU has developed process models using WINGEMS, a process modeling program that is well-accepted by the pulp and paper industry. While WINGEMS is well-develop for the production of pulp, for heat and water integration and recycle, and for the chemical recovery cycle, it does not have modules that effectively model enzyme hydrolysis, fermentation or distillation. At the same time the US DOE National Renewable Energy Laboratory (NREL) has developed two very detailed process models for the production bioethanol; one using enzyme hydrolysis, fermentation and distillation (Biochemical Processing), and the second using biomass gasification followed by the catalytic conversion of syngas to ethanol (Thermochemical Processing). These process models were developed using ASPEN processing modeling software. While these ASPEN models are well-developed they can not be easily integrated into a WINGEMS model, and vice versa. The goal of this project is to use the strengths of both WINGEMS and ASPEN models to provide more accurate process model the biochemical or thermochemical conversion of woody biomass to ethanol. This proposal is focused on funding graduate students.
The goal of this work will be to begin the process of integrating the information contained in the WINGEMS and ASPEN process models to develop a single process model that can accurately model the biochemical or thermochemical conversion of biomass to ethanol. Although, at this point it is not clear how this integration should be done. This collaboration will allow Dr. Adrianna Kirkman, an expect in WINGEMS and the technical lead on the process modeling work that has been done at NCSU, to work with the NREL staff for three weeks and develop a plan for the integration of these two modeling approaches.
The project comprises tasks pertaining to split sulfidity and polysulfide cooking, titanate chemistry and kinetics, and long term testing and engineering evaluation of the integrated steam reforming and direct causticization technology for economical and sustainable pulp production. Laboratory pulping studies will be conducted to maximize the benefits to pulping of the availability of sulfur-free and sulfur-rich liquors. The following options will be studied: Split sulfidity: The sulfidity will be varied in the three phases of pulping to quantify the benefits. The use of sodium carbonate in the initial phase will also be evaluated to minimize the causticization requirement. Polysulfide pulping: The benefits of high dosages of polysulfide on yield will be confirmed for both conventional pulping and modified pulping processes. Synergistic additives (AQ) and two-stage polysulfide pulping will be evaluated. Mill wide material and energy balances will be done to quantify the impacts on the overall mill operations and economics. A WinGEMS block will be developed to simulate the gasifier.
In the conventional kraft recovery cycle, the sodium and the sulfur ratio is fixed by the sulfidity of the liquor. Using black liquor gasification the sodium and the sulfur can be split into two separate fractions. This separation of the sodium and the sulfur creates some opportunities in the pulping process, which can lead to production cost savings or improved operations. The splitting of the sodium and the sulfur can be taken advantages of with the following technologies: Split Sulfidity Pulping Polysulfide Pulping Alkaline Sulfite Pulping : Alkaline Sulfite- AQ (AS-AQ) or Mini-Sulfite Sulfide AQ Process (MSS-AQ) Both the AS-AQ and the MSS-AQ process has however some unique features.. Pulp yield for linerboard is 10% pt higher than kraft at equivalent Kappa number and strength properties. The brightness of the AS-AQ/MSS-AQ linerboard pulp at 40 % ISO is considerably higher than the brightness of the corresponding kraft pulp: 18% ISO. Pulping studies will be conducted in the laboratory scale to optimize the operating conditions to maximize the benefits to pulping from splitting the sodium and the sulfur. The following options will be studied: Conventional kraft: Linerboard and bleachable pulps from softwood and bleachable pulps from hardwood will be prepared. These pulps will be evaluated for yield, appropriate strength properties and bleachability where appropriate. These results will be used as the base line for all the other comparisons. MSS-AQ pulping: Evaluate the potential for producing pulps with varying kappa number for both softwood using the MSSAQ pulping. The amount of sulfite and sulfide required and the total amount of chemical required for the various grades will be studied since this will affect the liquor balance of the gasification process. In all cases the yields and the strength properties will be monitored. .