Joelis Velez Diaz

About Me:  My homeland is Puerto Rico, I was born and raised there in Cidra which is in the center of the island. Due to Hurricane Maria, I moved to Massachusetts in 2018, I started my college career in 2020 at WPI. Where I am working towards my chemical engineering degree, environmental concentration, and materials minor, as well as the WPI teacher preparation program to teach high school chemistry by 2024.


About the Lab:  The Timko Lab is a chemical engineering lab, focusing on the conversion of waste to energy. The lab specializes in Hydrothermal processing, including Hydrothermal Liquefaction (HTL) and Carbonization. The goal of the lab is to optimize the yield of valuable products in the form of fuels and chemicals, through chemistry and processes engineering techniques.

Project:  The research domain is chemical engineering, mechanical, and materials engineering, accompanying the focus of guaranteeing everyone inexpensive, trustworthy tenable, and modernized electricity with the use of green waste and food waste by converting it to energy creating no contamination. The substantial motivation for this research is the planet earth and all organisms that coexist in it, climate change is a threat to all and now more than ever we must combat using knowledge, research, and STEM to acquire a better future. Therefore, the purpose of this research is to achieve green waste and food waste characterization to obtain an affordable and sustainable form of energy promoting environmental justice. Through hydrothermal liquefaction (HTL), bio-oil can be produced from food waste and energy-dense green waste feeds such as yard clippings and agricultural waste. This research aims to convert lignocellulosic wastes for energy production into usable energy by auto-thermal HTL. An aqueous phase with a sizable amount of useable carbon is a byproduct of HTL. Existing studies only quantify total carbon, leaving the chemical identity of the carbon unknown, and a significant gap in our understanding of aqueous analysis. After separation with vacuum filtration and solvent extraction, the resulting oil and aqueous products will be analyzed using gas chromatography-mass spectrometry (GC-MS), identifying the mechanism at the molecular level. By evaluating various reaction times and percentages of imputed solid waste, a feasible system that maximizes oil production and quality will be created, hence producing clean energy.

Weekly Updates: This presentation Six Week Schedule.pptx, illustrates what was accomplished per day, the reaction timeline, images, and preliminary results.

  • Week 1 (July 6-7): Attended RET orientation on July 6th, and Professional Development (PD) Session about Integrated STEM on July 7th. After the PD session I prepared my lab area and equipment, to then analyze more scholarly works and the data obtained last year.
  • Week 2 (July 10-14): On July 10th, I started carrying out more reactions after careful consideration of the results of last year. During this week I performed 4 HTL reactions at a temperature of 275°C, but 2 of them used a different feedstock to be able to compare two different types of green waste (AGW vs BDP GW). Evaluated the data from these 4 reactions of HTL and graphed it in excel to be able to contrast it to the results obtained with HTL+. Additionally, I attended the PD session about the engineering design process.
  • Week 3 (July 17-22): Finalized presentation with the results of week 2 and met up with advisor to discuss it. Completed 5 HTL reactions all at 300°C, 2 of them with green waste (BDP GW), and 3 with a mix of food waste and green waste on a 3:1 ratio. Diluted 2 samples of bio-crude to prepare it for the GC/MS analysis.
  • Week 4 (July 24-29): Executed 6 reactions, 4 of them being HTL+ and 2 HTL (all 60 minutes reactions at 300°C), but utilizing different feedstocks as it’s portrayed on the six week schedule. Diluted 4 samples of bio-crude for GC/MS analysis. Also, I attended the PD session about the 2-D Assessment and the Research Coffee Session with Erin Solovey where we discussed the making of the poster. Thereafter, I sent samples to Midwest Micro Lab for elemental analysis and I meet with the advisor to discuss the results thus far.
  • Week 5 (July 31, August 1-5): Conducted 4 reactions, to conclude the reactor runs with a total of 19 trials having duplicates of each variable condition. In addition, I performed the dilutions of the bio-crude oil to characterize all samples, received training again on how to operate the GC/MS machine, and tested all the samples. TOC is another test that also has to be done to determine the total organic carbon in the aqueous phase and close the carbon balance, hence I had to do the Civil, Environmental, and Architectural Engineering (CEAE) lab training in order to be able to have access to their TOC equipment. To conclude the week I attended the REU poster presentations, analyzed the data I obtained through my experiments, and improved my excel document together with the graphs.
  • Week 6 (August 7-16): This week was mainly focused on working and enhancing the poster before the submission. Thus, I completed a draft of the poster on Tuesday, before presenting it in the Research Coffee Session for feedback. Having received feedback on it I made changes according to that and proceeded to submit the finalized poster on Wednesday after also obtaining input from my advisor. The rest of the week I worked on the lesson plans, and meet with Donna Taylor on Friday to review it.
  • Week 7 (August 17-23):

Poster and Lesson Plan:

(Link RET Lesson Plan Handout)

(Link RET Poster)